1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#ifndef QSET_H
5#define QSET_H
6
7#include <QtCore/qhash.h>
8#include <QtCore/qcontainertools_impl.h>
9
10#include <initializer_list>
11#include <iterator>
12
13QT_BEGIN_NAMESPACE
14
15
16template <class T>
17class QSet
18{
19 typedef QHash<T, QHashDummyValue> Hash;
20
21public:
22 inline QSet() noexcept {}
23 inline QSet(std::initializer_list<T> list)
24 : QSet(list.begin(), list.end()) {}
25 template <typename InputIterator, QtPrivate::IfIsInputIterator<InputIterator> = true>
26 inline QSet(InputIterator first, InputIterator last)
27 {
28 QtPrivate::reserveIfForwardIterator(this, first, last);
29 for (; first != last; ++first)
30 insert(*first);
31 }
32
33 // compiler-generated copy/move ctor/assignment operators are fine!
34 // compiler-generated destructor is fine!
35
36 inline void swap(QSet<T> &other) noexcept { q_hash.swap(other.q_hash); }
37
38#ifndef Q_QDOC
39 template <typename U = T>
40 QTypeTraits::compare_eq_result_container<QSet, U> operator==(const QSet<T> &other) const
41 { return q_hash == other.q_hash; }
42 template <typename U = T>
43 QTypeTraits::compare_eq_result_container<QSet, U> operator!=(const QSet<T> &other) const
44 { return q_hash != other.q_hash; }
45#else
46 bool operator==(const QSet &other) const;
47 bool operator!=(const QSet &other) const;
48#endif
49
50 inline qsizetype size() const { return q_hash.size(); }
51
52 inline bool isEmpty() const { return q_hash.isEmpty(); }
53
54 inline qsizetype capacity() const { return q_hash.capacity(); }
55 inline void reserve(qsizetype size);
56 inline void squeeze() { q_hash.squeeze(); }
57
58 inline void detach() { q_hash.detach(); }
59 inline bool isDetached() const { return q_hash.isDetached(); }
60
61 inline void clear() { q_hash.clear(); }
62
63 inline bool remove(const T &value) { return q_hash.remove(value) != 0; }
64
65 template <typename Pred>
66 inline qsizetype removeIf(Pred predicate)
67 {
68 return QtPrivate::qset_erase_if(*this, predicate);
69 }
70
71 inline bool contains(const T &value) const { return q_hash.contains(value); }
72
73 bool contains(const QSet<T> &set) const;
74
75 class const_iterator;
76
77 class iterator
78 {
79 typedef QHash<T, QHashDummyValue> Hash;
80 typename Hash::iterator i;
81 friend class const_iterator;
82 friend class QSet<T>;
83
84 public:
85 typedef std::forward_iterator_tag iterator_category;
86 typedef qptrdiff difference_type;
87 typedef T value_type;
88 typedef const T *pointer;
89 typedef const T &reference;
90
91 inline iterator() {}
92 inline iterator(typename Hash::iterator o) : i(o) {}
93 inline iterator(const iterator &o) : i(o.i) {}
94 inline iterator &operator=(const iterator &o) { i = o.i; return *this; }
95 inline const T &operator*() const { return i.key(); }
96 inline const T *operator->() const { return &i.key(); }
97 inline bool operator==(const iterator &o) const { return i == o.i; }
98 inline bool operator!=(const iterator &o) const { return i != o.i; }
99 inline bool operator==(const const_iterator &o) const
100 { return i == o.i; }
101 inline bool operator!=(const const_iterator &o) const
102 { return i != o.i; }
103 inline iterator &operator++() { ++i; return *this; }
104 inline iterator operator++(int) { iterator r = *this; ++i; return r; }
105 };
106
107 class const_iterator
108 {
109 typedef QHash<T, QHashDummyValue> Hash;
110 typename Hash::const_iterator i;
111 friend class iterator;
112 friend class QSet<T>;
113
114 public:
115 typedef std::forward_iterator_tag iterator_category;
116 typedef qptrdiff difference_type;
117 typedef T value_type;
118 typedef const T *pointer;
119 typedef const T &reference;
120
121 inline const_iterator() {}
122 inline const_iterator(typename Hash::const_iterator o) : i(o) {}
123 inline const_iterator(const const_iterator &o) : i(o.i) {}
124 inline const_iterator(const iterator &o)
125 : i(o.i) {}
126 inline const_iterator &operator=(const const_iterator &o) { i = o.i; return *this; }
127 inline const T &operator*() const { return i.key(); }
128 inline const T *operator->() const { return &i.key(); }
129 inline bool operator==(const const_iterator &o) const { return i == o.i; }
130 inline bool operator!=(const const_iterator &o) const { return i != o.i; }
131 inline const_iterator &operator++() { ++i; return *this; }
132 inline const_iterator operator++(int) { const_iterator r = *this; ++i; return r; }
133 };
134
135 // STL style
136 inline iterator begin() { return q_hash.begin(); }
137 inline const_iterator begin() const noexcept { return q_hash.begin(); }
138 inline const_iterator cbegin() const noexcept { return q_hash.begin(); }
139 inline const_iterator constBegin() const noexcept { return q_hash.constBegin(); }
140 inline iterator end() { return q_hash.end(); }
141 inline const_iterator end() const noexcept { return q_hash.end(); }
142 inline const_iterator cend() const noexcept { return q_hash.end(); }
143 inline const_iterator constEnd() const noexcept { return q_hash.constEnd(); }
144
145 iterator erase(const_iterator i)
146 {
147 Q_ASSERT(i != constEnd());
148 return q_hash.erase(i.i);
149 }
150
151 // more Qt
152 typedef iterator Iterator;
153 typedef const_iterator ConstIterator;
154 inline qsizetype count() const { return q_hash.size(); }
155 inline iterator insert(const T &value)
156 { return q_hash.insert(value, QHashDummyValue()); }
157 inline iterator insert(T &&value)
158 { return q_hash.emplace(std::move(value), QHashDummyValue()); }
159 iterator find(const T &value) { return q_hash.find(value); }
160 const_iterator find(const T &value) const { return q_hash.find(value); }
161 inline const_iterator constFind(const T &value) const { return find(value); }
162 QSet<T> &unite(const QSet<T> &other);
163 QSet<T> &intersect(const QSet<T> &other);
164 bool intersects(const QSet<T> &other) const;
165 QSet<T> &subtract(const QSet<T> &other);
166
167 // STL compatibility
168 typedef T key_type;
169 typedef T value_type;
170 typedef value_type *pointer;
171 typedef const value_type *const_pointer;
172 typedef value_type &reference;
173 typedef const value_type &const_reference;
174 typedef qptrdiff difference_type;
175 typedef qsizetype size_type;
176
177 inline bool empty() const { return isEmpty(); }
178
179 iterator insert(const_iterator, const T &value) { return insert(value); }
180
181 // comfort
182 inline QSet<T> &operator<<(const T &value) { insert(value); return *this; }
183 inline QSet<T> &operator|=(const QSet<T> &other) { unite(other); return *this; }
184 inline QSet<T> &operator|=(const T &value) { insert(value); return *this; }
185 inline QSet<T> &operator&=(const QSet<T> &other) { intersect(other); return *this; }
186 inline QSet<T> &operator&=(const T &value)
187 { QSet<T> result; if (contains(value)) result.insert(value); return (*this = result); }
188 inline QSet<T> &operator+=(const QSet<T> &other) { unite(other); return *this; }
189 inline QSet<T> &operator+=(const T &value) { insert(value); return *this; }
190 inline QSet<T> &operator-=(const QSet<T> &other) { subtract(other); return *this; }
191 inline QSet<T> &operator-=(const T &value) { remove(value); return *this; }
192
193 friend QSet operator|(const QSet &lhs, const QSet &rhs) { return QSet(lhs) |= rhs; }
194 friend QSet operator|(QSet &&lhs, const QSet &rhs) { lhs |= rhs; return std::move(lhs); }
195
196 friend QSet operator&(const QSet &lhs, const QSet &rhs) { return QSet(lhs) &= rhs; }
197 friend QSet operator&(QSet &&lhs, const QSet &rhs) { lhs &= rhs; return std::move(lhs); }
198
199 friend QSet operator+(const QSet &lhs, const QSet &rhs) { return QSet(lhs) += rhs; }
200 friend QSet operator+(QSet &&lhs, const QSet &rhs) { lhs += rhs; return std::move(lhs); }
201
202 friend QSet operator-(const QSet &lhs, const QSet &rhs) { return QSet(lhs) -= rhs; }
203 friend QSet operator-(QSet &&lhs, const QSet &rhs) { lhs -= rhs; return std::move(lhs); }
204
205 QList<T> values() const;
206
207private:
208 Hash q_hash;
209};
210
211template <typename InputIterator,
212 typename ValueType = typename std::iterator_traits<InputIterator>::value_type,
213 QtPrivate::IfIsInputIterator<InputIterator> = true>
214QSet(InputIterator, InputIterator) -> QSet<ValueType>;
215
216template <typename T>
217size_t qHash(const QSet<T> &key, size_t seed = 0)
218noexcept(noexcept(qHashRangeCommutative(key.begin(), key.end(), seed)))
219{
220 return qHashRangeCommutative(key.begin(), key.end(), seed);
221}
222
223// inline function implementations
224
225template <class T>
226Q_INLINE_TEMPLATE void QSet<T>::reserve(qsizetype asize) { q_hash.reserve(asize); }
227
228template <class T>
229Q_INLINE_TEMPLATE QSet<T> &QSet<T>::unite(const QSet<T> &other)
230{
231 if (!q_hash.isSharedWith(other.q_hash)) {
232 for (const T &e : other)
233 insert(e);
234 }
235 return *this;
236}
237
238template <class T>
239Q_INLINE_TEMPLATE QSet<T> &QSet<T>::intersect(const QSet<T> &other)
240{
241 QSet<T> copy1;
242 QSet<T> copy2;
243 if (size() <= other.size()) {
244 copy1 = *this;
245 copy2 = other;
246 } else {
247 copy1 = other;
248 copy2 = *this;
249 *this = copy1;
250 }
251 for (const auto &e : std::as_const(copy1)) {
252 if (!copy2.contains(e))
253 remove(value: e);
254 }
255 return *this;
256}
257
258template <class T>
259Q_INLINE_TEMPLATE bool QSet<T>::intersects(const QSet<T> &other) const
260{
261 const bool otherIsBigger = other.size() > size();
262 const QSet &smallestSet = otherIsBigger ? *this : other;
263 const QSet &biggestSet = otherIsBigger ? other : *this;
264 typename QSet::const_iterator i = smallestSet.cbegin();
265 typename QSet::const_iterator e = smallestSet.cend();
266
267 while (i != e) {
268 if (biggestSet.contains(*i))
269 return true;
270 ++i;
271 }
272
273 return false;
274}
275
276template <class T>
277Q_INLINE_TEMPLATE QSet<T> &QSet<T>::subtract(const QSet<T> &other)
278{
279 if (q_hash.isSharedWith(other.q_hash)) {
280 clear();
281 } else {
282 for (const auto &e : other)
283 remove(value: e);
284 }
285 return *this;
286}
287
288template <class T>
289Q_INLINE_TEMPLATE bool QSet<T>::contains(const QSet<T> &other) const
290{
291 typename QSet<T>::const_iterator i = other.constBegin();
292 while (i != other.constEnd()) {
293 if (!contains(*i))
294 return false;
295 ++i;
296 }
297 return true;
298}
299
300template <typename T>
301Q_OUTOFLINE_TEMPLATE QList<T> QSet<T>::values() const
302{
303 QList<T> result;
304 result.reserve(size());
305 typename QSet<T>::const_iterator i = constBegin();
306 while (i != constEnd()) {
307 result.append(*i);
308 ++i;
309 }
310 return result;
311}
312
313Q_DECLARE_SEQUENTIAL_ITERATOR(Set)
314
315#if !defined(QT_NO_JAVA_STYLE_ITERATORS)
316template <typename T>
317class QMutableSetIterator
318{
319 typedef typename QSet<T>::iterator iterator;
320 QSet<T> *c;
321 iterator i, n;
322 inline bool item_exists() const { return c->constEnd() != n; }
323
324public:
325 inline QMutableSetIterator(QSet<T> &container)
326 : c(&container)
327 { i = c->begin(); n = c->end(); }
328 inline QMutableSetIterator &operator=(QSet<T> &container)
329 { c = &container; i = c->begin(); n = c->end(); return *this; }
330 inline void toFront() { i = c->begin(); n = c->end(); }
331 inline void toBack() { i = c->end(); n = i; }
332 inline bool hasNext() const { return c->constEnd() != i; }
333 inline const T &next() { n = i++; return *n; }
334 inline const T &peekNext() const { return *i; }
335 inline void remove()
336 { if (c->constEnd() != n) { i = c->erase(n); n = c->end(); } }
337 inline const T &value() const { Q_ASSERT(item_exists()); return *n; }
338 inline bool findNext(const T &t)
339 { while (c->constEnd() != (n = i)) if (*i++ == t) return true; return false; }
340};
341#endif // QT_NO_JAVA_STYLE_ITERATORS
342
343template <typename T, typename Predicate>
344qsizetype erase_if(QSet<T> &set, Predicate pred)
345{
346 return QtPrivate::qset_erase_if(set, pred);
347}
348
349QT_END_NAMESPACE
350
351#endif // QSET_H
352